sábado, 17 de abril de 2010

Systematic review finds no difference in nutritional value of organic vs. conventional foods

Organically produced foodstuffs are not richer in vitamins and minerals than conventionally produced foodstuffs, conclude researchers in a systematic review published in September 2009 in the American Journal of Clinical Nutrition.
With many people believing that organic foods have a higher content of nutrients and thus are healthier than conventionally produced foods, demand for organic produce is on the rise. However, scientists have not been equally convinced that this is the case as the research conducted in the field has not shown consistent results.
In order to assess potential differences in nutrient content between organic and conventional foods, researchers at London School of Hygiene & Tropical Medicine, UK, performed a systematic review of the literature. In such a review, the available scientific literature on the subject of interest is screened and the outcomes of all articles meeting predefined quality criteria analysed in a systematic fashion. Based on the results from such analyses a general evidence-based conclusion can be drawn. In the present review, 162 relevant studies (published 1958-2008) on the content of nutrients and other substances in organic versus conventional foodstuffs were identified, and 55 of these were of satisfactory quality to be included in the review. Studies on both crops and livestock products were considered.
The results of the systematic review only showed a lower nitrogen and higher phosphorus content in organic produce compared to conventionally grown foodstuffs. Contents of the following nutrients or other substances did not differ between the two categories: vitamin C, calcium, potassium, total soluble solids, copper, iron, nitrates, manganese, ash, specific proteins, sodium, plant non-digestible carbohydrates, β-carotene and sulphur.
In an initial phase of the analysis, when all 162 papers were included independently of their quality, organic foods showed higher levels of phytochemicals than did conventionally produced foodstuffs. However, when the quality of the studies was taken into account such association could no longer be detected. The researchers speculate that the differences observed likely resulted from different harvesting times and the use of different fertilisers. They also stated that these differences are unlikely to be of any importance for human health.
In conclusion, organic and conventional foods appeared equal in terms of nutritional value. However, different production methods may give rise to other differences not addressed in this review, e.g. environmental aspects.

Source: EUFIC

terça-feira, 13 de abril de 2010

Cod liver oil (n-3 fatty acids) as an non-steroidal anti-inflammatory drug sparing agent in rheumatoid arthritis

B. Galarraga, M. Ho, H. M. Youssef, A. Hill, H. McMahon, C. Hall, S. Ogston, G. Nuki, J. J. F. Belch

Objectives. Dose-dependant gastrointestinal and cardiovascular side-effects limit the use of NSAIDs in the management of RA. The n-3 essential fatty acids (EFAs) have previously demonstrated some anti-inflammatory and NSAID-sparing properties. The objective of this study was to determine whether cod liver oil supplementation helps reduce daily NSAID requirement of patients with RA.

Methods. Dual-centre, double-blind placebo-controlled randomized study of 9 months’ duration. Ninety-seven patients with RA were randomized to take either 10 g of cod liver oil containing 2.2 g of n-3 EFAs or air-filled identical placebo capsules. Documentation of NSAID daily requirement, clinical and laboratory parameters of RA disease activity and safety checks were done at 0, 4, 12, 24 and 36 weeks. At 12 weeks, patients were instructed to gradually reduce, and if possible, stop their NSAID intake. Relative reduction of daily NSAID requirement by >30% after 9 months was the primary outcome measure.

Results. Fifty-eight patients (60%) completed the study. Out of 49 patients 19 (39%) in the cod liver oil group and out of 48 patients 5 (10%) in the placebo group were able to reduce their daily NSAID requirement by >30% (P = 0.002, chi-squared test). No differences between the groups were observed in the clinical parameters of RA disease activity or in the side-effects observed.

Conclusions. This study suggests that cod liver oil supplements containing n-3 fatty acids can be used as NSAID-sparing agents in RA patients.

KEY WORDS: RA, Fish oil, n-3 fatty acids, NSAIDs

quinta-feira, 8 de abril de 2010

Fruit and Vegetable Intake and Overall Cancer Risk in the European Prospective Investigation Into Cancer and Nutrition (EPIC)

Background: It is widely believed that cancer can be prevented by high intake of fruits and vegetables. However, inconsistent results from many studies have not been able to conclusively establish an inverse association between fruit and vegetable intake and overall cancer risk.

Methods: We conducted a prospective analysis of the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort to assess relationships between intake of total fruits, total vegetables, and total fruits and vegetables combined and cancer risk during 1992–2000. Detailed information on the dietary habit and lifestyle variables of the cohort was obtained. Cancer incidence and mortality data were ascertained, and hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using multivariable Cox regression models. Analyses were also conducted for cancers associated with tobacco and alcohol after stratification for tobacco smoking and alcohol drinking.

Results: Of the initial 142 605 men and 335 873 women included in the study, 9604 men and 21 000 women were identified with cancer after a median follow-up of 8.7 years. The crude cancer incidence rates were 7.9 per 1000 person-years in men and 7.1 per 1000 person-years in women. Associations between reduced cancer risk and increased intake of total fruits and vegetables combined and total vegetables for the entire cohort were similar (200 g/d increased intake of fruits and vegetables combined, HR = 0.97, 95% CI = 0.96 to 0.99; 100 g/d increased intake of total vegetables, HR = 0.98, 95% CI = 0.97 to 0.99); intake of fruits showed a weaker inverse association (100 g/d increased intake of total fruits, HR = 0.99, 95% CI = 0.98 to 1.00). The reduced risk of cancer associated with high vegetable intake was restricted to women (HR = 0.98, 95% CI = 0.97 to 0.99). Stratification by alcohol intake suggested a stronger reduction in risk in heavy drinkers and was confined to cancers caused by smoking and alcohol.

Conclusions: A very small inverse association between intake of total fruits and vegetables and cancer risk was observed in this study. Given the small magnitude of the observed associations, caution should be applied in their interpretation.

Paolo Boffetta, Elisabeth Couto, Janine Wichmann, Pietro Ferrari, Dimitrios Trichopoulos, H. Bas Bueno-de-Mesquita, Fränzel J. B. van Duijnhoven, Frederike L. Büchner, Tim Key, Heiner Boeing, Ute Nöthlings, Jakob Linseisen, Carlos A. Gonzalez, Kim Overvad, Michael R. S. Nielsen, Anne Tjønneland, Anja Olsen, Françoise Clavel-Chapelon, Marie-Christine Boutron-Ruault, Sophie Morois, Pagona Lagiou, Androniki Naska, Vassiliki Benetou, Rudolf Kaaks, Sabine Rohrmann, Salvatore Panico, Sabina Sieri, Paolo Vineis, Domenico Palli, Carla H. van Gils, Petra H. Peeters, Eiliv Lund, Magritt Brustad, Dagrun Engeset, José María Huerta, Laudina Rodríguez, Maria-José Sánchez, Miren Dorronsoro, Aurelio Barricarte, Göran Hallmans, Ingegerd Johansson, Jonas Manjer, Emily Sonestedt, Naomi E. Allen, Sheila Bingham, Kay-Tee Khaw, Nadia Slimani, Mazda Jenab, Traci Mouw, Teresa Norat, Elio RiboliAntonia Trichopoulou